Consecutive wet deposition of nitrogen along half of China's coastal cities induced by Super Typhoon Muifa (2022) with multiple landfalls

Abstract

The extraordinary Super Typhoon (STY) Muifa (2022) made landfall four times and had a significant impact on the coastal regions from south to north of China. Although previous studies have demonstrated the ‘pumping effect’ of typhoons on the enhancement of reactive nitrogen (N_r) wet deposition over the ocean, it is uncertain how N_r deposition is influenced by typhoons that make prolonged mechanism due to multiple landfalls. In this study, the N_r wet deposition induced by STY Muifa was investigated from the perspective of in- and below-cloud processes based on the Nested Air Quality Prediction Modeling System with an online tracer‐tagging module. High volume of N_r wet deposition caused by Muifa migrated from south to north, passing over half of China's coastal cities. Compared to the typhoon generated vicinity, both mean values of the oxidized and reduced nitrogen wet deposition over the Typhoon affected regions were increased about 20.4 and 66.1 times after landfall even with the similar rainfall. Emissions from the four landfall areas of China contributed to the majority of N_r wet deposition with significantly enhanced proportion of in-cloud deposition. The strong pumping effect of typhoon to the N_r deposition along the coastal areas and the risk of ecosystem effects requires further researches and higher demands on the control of nitrogen emissions of National Industrial Park, which usually located in China's coastal cities.